Big Bore Kits from Rocky Mountain ATV/MC

GYTR Head

Expensive engine mod but if you are serious about powering up your YZ grab this and get to the front. Need to use VP u4.4 but you should already be using that if your racing at all . Be sure to set the new mapping to the ECU !

Best mod ever

Athena 290 big bore wr/yz

I have ran this big bore for three years and have great success with it, makes great bottom end and mid range power. I have ran it on my 08 yz250f with a wr trans and rekluse clutch and hot cams, awesome woods bike.